i cant load 21w05b

For some reason today, I cant load 21w05b anymore. Either it's taking forever to load or it's not working at all. The other installations I have can be loaded without taking a long time. When I click "Play" when i have the installation set to 21w05b, it doesn't load the game. I've tried restarting my computer but that didn't fix the problem. Now I cant play on old worlds because there STILL isn't a path for generating new terrain in old worlds, and it's been like that for over a month.